Question 1079030
P(Drawing two pens of the zame color)= P(Drawing two red pens or Drawing two blue pens or Drawing two green pens)= 3*P(Drawing two red pens)=

3*(12/36*11/35)=11/1260= 0.00873=8.73%.

When you have options you must add this probabilities,as every option has the same probability, you multiply one of them by 3.

In your first drawing you have 12 red pens and 36 pens. so the Probability is 12/36. on your second drawing, you have 11 red pens and 35 pens, so the probabiliy is 11/35. You need that both drawing been simultaneous. So you multiply this two results.

@natolino_